Infrared heating apparatus

ABSTRACT

An apparatus (10,80,150) for heating an object with black body infrared radiation. The apparatus (10,80,150) comprises a radiation source (42,96,158) for generating black body infrared radiation and a honeycomb stagnating element (48,132,160) for preventing transmission of heat by convection from the radiation source (42,96,158). Also various methods for using the apparatus (10,80,150) are disclosed.

RELATED APPLICATION

This application is a divisional application of application Ser. No.08/155,924 filed Nov. 22, 1993 and now U.S. Pat. No. 5,413,587 issuedMay 9, 1995.

TECHNICAL FIELD

The subject invention relates to an apparatus for generating infraredradiation, and more particularly to an apparatus and method used forirradiating an object with black body infrared radiation.

BACKGROUND ART

The therapeutic benefits attributable to hyperthermia, i.e. elevatedbody temperature, as a treatment for many types of bodily disorders havebeen known for centuries. The common fever elegantly exemplifies thetherapeutic benefits of elevated body temperature. In the presence ofinfection by common infectious agents, e.g., cold viruses, the humanimmune system responds by elevating the body's core temperature to aidin the resolution of the infection.

Throughout history, practitioners have sought to induce fever or anartificial state of fever in order to increase body temperature to treatbodily disorders. An early form of treatment for syphilis illustratesthis fact. Historically, practitioners attempted to artificially elevatethe body temperature of an individual infected with syphilis by suchmedieval methods as infecting the patient with an infectious agent, suchas malaria, thereby to induce a fever in an attempt to cure thesyphilis. This method, however, even if successful in curing thesyphilis, left the patient chronically infected with the incurabledisease of malaria.

Modern approaches toward achieving localized hyperthermia in biologicaltissues include dielectric heating, microwave diathermy, ultrasonicheating, and the application of hot compresses or "hot packs". All ofthese methods have particular clinical applications, but each exhibitsone or more disadvantages.

Dielectric heating involves placing capacitative electrodes around thetissue to be treated. An alternating R.F. (radio frequency) current ofbetween 10⁶ Hz to 10⁹ Hz is applied across the tissues and induces adielectric loss within the tissues. This dielectric loss within thetissues results in heat generated within the tissues themselves. Theexcellent tissue penetration afforded by this heating modality make itan obvious choice for the deep heating of tissues. However, the need foraccuracy in the placement of the electrodes and the attendant loss ofcontrol of the field location within the tissues associated withelectrode placement, make heating a specific region of tissue difficult.

Microwave diathermy is an extension of the dielectric heating method.Microwave diathermy employing R.F. frequencies in the range of 10⁹ Hz to10¹⁰ Hz were found to be very efficacious, but the result were plaguedby various troubling effects which often outweighed the benefits. Humantissues exhibit a highly variable impedance or radiation resistance tothe particular wavelengths of electromagnetic radiation employed inmicrowave diathermy. This variability in impedance may causeconstructive interference, destructive interference, or even resonancewithin the tissues resulting in damaging localized heating or pain.Additionally, if the subject undergoing microwave diathermy treatmenthas any metallic implants such as hip joint replacements plates or pins,these implants would further concentrate the radiation and cause damageto local tissues. Microwave diathermy was commonly used until concernsover the effects of high electromagnetic (e.m.) field intensities onbiologic subjects dampened the enthusiasm for this modality.

Ultrasonic diathermy is a commonly employed heating modality used inphysical therapy settings to locally heat sub-surface or deep tissues toprovide pain relief. These ultrasonic devices emit energy at frequenciesfrom between 2×10⁴ to 10⁷. Heating of the tissues occurs because ofvisco-elastic loss within the tissues in response to mechano-elasticwaves coupled into the tissues from an ultrasonic transducer. Thevariability of the impedance of human tissues can give rise toreflections at tissue interfaces such as at the muscle-bone interface ormuscle-fat interface. These reflections can result in localizedconcentrations of energy referred to as "hot spotting" which can lead totissue damage or subject the patient to unnecessary pain. In addition,in order to implement this modality of heating tissue, the transducermust be continuously moved over the treatment area and a messy couplinggel must be applied to the patient in order for the patient to receivethe ultrasonic waves.

Both the radio frequency diathermy devices and ultrasonic diathermydevices are relatively complex and costly to manufacture and do not lendthemselves to unsupervised or non-medical applications of treatment.

People use heating pads and "hot packs" for treating a variety of aches,pains, and ailments. The benefits of these devices are limited; however,since the heat is deposited on the surface of the skin and mustpenetrate to the underlying tissues by conduction, effective treatmentis limited skin tolerance to elevated temperatures.

Infrared radiation provides another modality for inducing localizedhyperthermia in biological tissues. The epidermal tissue of the skinabsorbs much of the infrared radiation of wavelengths shorter than 3 μm.In order to increase the internal temperature of biological tissues and,thereby, to induce localized hyperthermia without causing substantialheating of the epidermal tissue, application of infrared radiation ofwavelengths in the range of 3-30 μm to the biological tissues aredesired. Infrared radiation in the range of 3-30 μm is only partlyabsorbed by water molecules. Since epidermal tissue contains a greaterproportion of water molecules than does deeper tissues such as fat, theinfrared radiation in this range is not substantially absorbed by theepidermal tissue of the skin. A typical example of an infrared radiationsource used for localized heating of biological tissues is a common heatlamp. The common heat lamp provides an inexpensive mechanism forgenerating infrared radiation. However, as is the case with all otherprior art infrared radiation sources used for inducing localizedhyperthermia, the prior art infrared sources generate a broad spectrumof infrared radiation including short wavelength infrared radiation ofwavelengths less than 3 μm which overheat the epidermal tissues, i.e.,the skin.

U.S. Pat. No. 4,489,234 to Harnden, Jr. et al. teaches a particularinfrared wavelength heating and/or cooking device utilizing honeycombtube members for supporting glass cover plates. However, the deviceproduces infrared radiation of wavelengths substantially less than 3 μm.The wavelengths generated are best suited to heating and/or cooking butwould cause serious damage if applied to biological tissues.Unfortunately, both the epidermal tissues, i.e. the skin, and theunderlying tissues absorb infrared radiation of wavelengths shorter than3 μm. As a result, the prior art infrared radiation generating devicesdetrimentally heat the epidermal tissues of the skin and cause thetemperature of the skin to increase to levels causing discomfort orepidermal tissue damage. Because the epidermal tissue of the skinabsorbs infrared radiation of wavelengths less than 3 μm as well as dothe internal tissues, the prior art infrared hyperthermia devices limitadministration of infrared radiation to less than the efficaciousamounts necessary for achieving therapeutic benefit.

Medium and long wavelength infrared emitters are commonly used inindustry to cure coatings and heat products. These infrared emitterstypically utilize a heated, highly emissive surface to couple radiationthrough the air to object being heated. However, convective coupling ofthe air surrounding the emitter heats the air which can heat nearbyobjects by convection and conduction.

Lasers are an ideal source of monochromatic long wavelength infraredradiation. In particular, CO₂ lasers are a good source of monochromaticlong wave infrared radiation. However, lasers of this type produce avery intense and discrete beam of focused infrared radiation which couldcause tissue damage. These intense and discrete beams of infraredradiation could be diffused by expanding or scanning the beam, but thisreduces the power intensity (W/m²) making the laser a less effectivemodality of treatment. Lasers emit essentially at one wavelength. Thedisadvantage of emitting only a single wavelength, as opposed to a broadspectrum emitting source, is that the wavelength may be absorbed by aparticular molecule or tissue. A broad spectrum emitting sourceincreases the probability that the desired wavelengths will reach thetissues to be treated. Additionally, at this time, the high cost of theequipment, the complexity of the apparatus, i.e., sealed sources andinfrared optics, and the need for trained operators preclude lasers frombeing a practical modality for generating long wavelength infraredradiation for inducing localized hyperthermia.

Efficiency of the radiation source is another significant problemassociated with prior art radiant infrared wavelength generatingdevices. Typically, radiant infrared generating sources must bemaintained in a temperature range of 300°-3000° K. to maximize radiativeemission of infrared radiation. In particular, a radiation sourcedesigned to operate in the temperature range of 300°-3000° K. will loseefficiency due to convective heat loss to the surrounding air. This lossof efficiency due to convective and conductive heat loss requires alarge input of electrical power to constantly maintain the temperatureof the radiation generating source. Prior art devices have attempted toremedy this problem by operating the radiation source in a vacuum, i.e.,an air-free environment. Typically, the radiation source is operatedwithin a sealed and air-free or vacuum environment enclosed behind aninfrared transparent window. While vacuum sealing is an effectivemechanism for increasing the efficiency of a radiant infrared wavelengthgenerating source for producing infrared radiation of <3 μm, however,longer wavelength infrared radiation in the range of 3-30 μm is absorbedby most practical window materials. Therefore, using this means forgenerating infrared radiation having wavelength substantially in therange of 3-30 μm for heating internal biological tissues with minimalheating of the external tissues is not practicable. While using a vacuumis effective at reducing convective and conductive heat losses from theradiation generating source, its use is impractical because mostpractical materials will not allow for the transmission of infraredwavelengths in the range of 3-30 μm. Window materials suitable fortransmission of medium and long wavelength infrared radiation areavailable such as silicon, germanium, zinc selenide and other exoticmaterials. These materials, however, are physically unable to withstandthe pressures associated with maintaining a vacuum in a sealed,evacuated radiation source.

In order to maximize the efficiency of a radiant radiation generatingsource capable of emitting infrared radiation of wavelengths in therange of 3-30 μm, it is necessary to find an alternative means forincreasing efficiency of the radiation source capable of both preventingconvective heat losses from the radiation generating source byinhibiting air flow at the radiation source and, at the same time,allows infrared radiation of wavelengths in the range of 3-30 μm to passthrough it.

SUMMARY OF THE INVENTION

According to the present invention, an apparatus is provided for heatingan object with black body infrared radiation. The apparatus comprises aradiation source for generating black body infrared radiation andemitting the radiation for transmission into a first zone and thereafterinto a second zone to heat a body located in the second zone by blackbody infrared radiation. The apparatus is characterized by stagnatingmeans disposed in the first and second zones to establish a continuousand homogenous fluid medium extending from the radiation source into thefirst zone and into the second zone. The stagnating means stagnates theflow of the fluid medium in the first zone to limit transmission of heatby convection from the radiation source and from the first zone to thesecond zone.

The resulting apparatus provides an effective mechanism for increasingthe temperature of internal biological tissue without causing discomfortor damage to the overlying external biological tissues.

The present invention also includes a method of utilizing the novelapparatus for heating a body with black body infrared radiation.

The present invention also includes a method for heating internalbiological tissues of the type also having external tissues withoutincreasing the temperature of the external tissues above a predeterminedlimit where discomfort or damage to the external tissues occurs.

The present invention additionally includes a method for increasinglocalized blood circulation in internal biological tissues of the typealso having external tissues without increasing the temperature of theexternal tissues above a predetermined limit where discomfort or damageto the external tissues occurs.

The present invention additionally includes a method for increasinglocalized blood circulation in internal biological tissues of a penishaving external tissues without increasing the temperature of theexternal tissues above a predetermined limit where discomfort or damageto the external tissues occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view of the heating apparatus of the presentinvention mounted on an adjustable stand, and showing a subject to betreated;

FIG. 2 is a side cross-sectional view of the heating apparatus of theinvention;

FIG. 3 is a front elevational view of the heating apparatus partiallybroken away;

FIG. 4 is a fragmentary perspective view of a portion of the stagnatingmeans of the invention;

FIG. 5 is a cross-sectional view of another embodiment of the heatingapparatus of the present invention;

FIG. 6 is a cross-sectional view taken substantially along line 6-6 ofFIG. 5; and

FIG. 7 is a cross-sectional view of still another embodiment of theheating apparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, an infrared heating apparatus 10 according to theinvention is shown mounted on a supporting stand 12 having a base 14comprised of a plurality of legs 16 mounted on casters 18. A verticalpost 20 is affixed to the base 14 having a clamping sleeve 22 slidablymounted thereon and a clamp 24 fixing the clamping sleeve at the desiredheight on the vertical post 20. A lateral arm 26 is also slidablymounted in the clamping sleeve 22 and affixed in the desired position bymeans of a clamp 28. Adjustable coupling means 30 is also provided atthe end of each lateral arm 26 and is in turn affixed to the infraredheating apparatus 10. A table 32 is also shown supporting a subject 34to be treated.

Referring to FIG. 2, the heating apparatus 10 of the invention is shownin greater detail, and comprises a housing 40 which may be formed of atemperature resistant material such as aluminum, or any other suitablematerial. Inside the housing 40 is a radiation source. The radiationsource is a radiation generating element 42 comprised of a base block 44formed of a material such as ceramic fibers or any other suitablematerial, and having a sinuated heating element 46 dispersedtherethrough, as shown in greater detail in FIG. 3.

The heating apparatus 10 additionally comprises stagnating meanscomprising an air stagnating element 48 also disposed in the housing,comprising a plurality of conduits or tubes 70 in a coherent arraydefining a first zone 77 which includes a pocket 73, as shown in greaterdetail in FIG. 4. The tubes or conduits 70 have first 71 and second 72open ends and a wall portion 74 extending therebetween. The tubes 70 maybe of any desired cross-section, although a hexagonal cross-section isthe preferred form. The stagnating element 48 is held in place againstthe radiation generating element 42 by compression. An insulation pad 50formed of ceramic fibers and having a stainless steel specular reflectorplate 52 affixed thereto is disposed in the housing 40 in spaced-apartrelationship behind the surface of the radiation generating element 42.A thermo-sensing probe 54 is positioned in the base block 44, and isconnected to an electrical temperature control unit 56 of the type wellknown in the art. An air circulating means for circulating air over theobject being irradiated is mounted within the housing 40. The aircirculating means comprises a fan housing 58 having a motor cooling fan60 mounted therein, and a cylindrical fan 57, shown in greater detail inFIG. 3, the air therefrom passing via duct 59 through an adjustablelouvre assembly 62.

Referring to FIGS. 3 and 4, the infrared heating apparatus 10 of theinvention is shown in a front elevational view. The air stagnatingelement 48 formed of the plurality of tubes 70, and the adjustablelouvre assembly 62 are shown in greater detail.

Referring to FIGS. 5 and 6, another embodiment of the infrared heatingapparatus 10 is shown and indicated by the reference numeral 80. Theapparatus 80 of the second embodiment comprises a housing 82 having aplurality of cooling fins 84. Within the housing 82 is a base insulatingplug 86 of a material such as ceramic fiber, a sleeve 88, and aplurality of apertures 89 with set screws 90 located therein. Adjustablysupported on the set screws 90 is a slidable cylinder 92 creating an airspace 91 between the slidable cylinder 92 and the sleeve 88. An aperture83 is provided in the housing 82 so that a power cord 87 can beconnected to a lamp socket 94 disposed in the slidable cylinder 92. Thelamp socket 94 is mounted on an end 95 of the cylinder 92. A radiationsource 96 comprising a lamp 97 having a base section 98 andradiation-emitting section 99 is mounted in the socket 94. A tubularelement 100, mounted around the lamp 96, is formed of a metal havingapertures 114 provided therein, and serves to absorb visible light andto emit infrared light therefrom and will be subsequently described indetail.

A stagnating means comprises a tubular air stagnating element 132mounted around the lamp 96 and the tubular element 100 between a rearcap 116 and a front cap 122. The rear cap 116 has a central aperture 118provided therein and an axial flange 120 affixed to the slidablecylinder 92 by welding or any other suitable means. The air stagnatingelement 132 is formed as an octagonal tube comprised of eight individualsections 133. A thermo-sensing probe 124 is positioned in contact withthe tubular element 100, and is connected to a remote electricaltemperature control unit, not shown. A wire 125 connected to thethermo-sensing probe 124 exits the housing 82 and the insulating block86 through an aperture 85 and is connected to the remote electricaltemperature control unit, not shown, to be subsequently described indetail. A reflector 126 having a central aperture 128 is mounted to thehousing 82 for directing the infrared light emitted from radiationgenerating element 96 in a narrow beam or focusing the radiation into aspot. The reflector 126 may have a parabolic, hyperbolic, elliptical, orany other suitable form depending on the application for which theapparatus is used.

Referring to FIG. 7, a third embodiment of the infrared heatingapparatus 10' of the present invention is indicated by the referencenumeral 150. The apparatus 150 comprises an elongate support 152 and aradiation source comprising a planar radiation generating element 158similar to that designated by the numeral 42 in FIG. 2. The planarradiation generating element 158 is affixed to a pair of air stagnatingelements 160 similar to that designated by the numeral 48 of FIG. 2. Thestagnating elements 160 are mounted one on each surface 159 of theradiation generating element 158 and are held in place with front cap166 and rear cap 168. The support 152 has a first 154 and second 156ends. The radiation generating element 158 is affixed to the first end154 of the elongate support 152. The rear cap 166 may be affixed to thefirst end 154 of the elongate support 152 by welding, crimping, or anyother suitable means known in the art. A reflector 162 having a "V"shaped cross-section is mounted to the elongate support 152. Electricalcontrol means, not shown, but similar to that used with respect to theembodiment shown in FIGS. 5 and 6 are utilized in conjunction with athermosensing probe 170, which is embedded in the radiation generatingelement 158.

The terms black body and black body radiation used to describe theradiation source and the radiation emitted from the source but are moreaccurately termed as a grey body or grey body radiation. At a giventemperature, the grey body has the same spectral characteristics as atrue black body but at a lower emissivity. Therefore, any referencewithin to a black body or black body radiation should be understood tomean a grey body or grey body radiation.

The black body infrared radiation generating apparatus comprises aradiation generating element 42 and a stagnating element 48. Theradiation generating element 42 is a black or grey body thermal sourceand, therefore, the radiation source behaves according to theStefan-Boltzman law.

E=nT⁴

where:

E=total energy per area (W/m²);

n=5.67×⁻⁸ W/(m² K⁴);

T=operating temperature in °K.

Under the Stefan-Boltzman law, the maximum wavelength is a function ofthe absolute temperature of the black or grey body radiation source. Themaximum wavelength is the wavelength at which the maximum power per unitarea is generated for a given operating temperature.

Maximum Wavelength=c/(const. X T)

where:

c=3.00×10⁸ m/s;

const.=5.88×10¹⁰ Hz/°K.

T=operating temperature in °K.

Following the Stefan-Boltzman law, the temperature of the radiationgenerating element 42 in the apparatus 10 is maintained in a range ofabout 500°-1000° K. Maintaining the temperature of the radiationgenerating element 42 in this temperature range yields a black bodyinfrared radiation emission spectrum with maximum emitted wavelengths(λ_(max)) of approximately 3-6 μm. The maximum emitted wavelengths(λ_(max)) are the peak emissions, however, radiation emitted from ablack or grey body radiation source is emitted in a somewhat continuousspectrum. Therefore, by the nature and physics of a black or grey bodyradiation source, a range of wavelengths are emitted, not amonochromatic or single wavelength of radiation. The actual continuumemission spectrum for a black or grey body source with maximum emittedwavelengths (λ_(max)) of approximately 3-6 μm would be approximately1-30 μm. Additionally, since E, the total energy per area, varies as afunction of the temperature to the fourth power (T⁴), maintaining thetemperature of the source is critical to achieving maximum efficacy ofthe radiation source. In other words, fluctuations in the temperature ofthe radiation source are reflected exponentially in the total energy perarea or power output of the radiation source. For this reason,maintaining the temperature of the radiation source is critical tomaximizing efficacy in a given application.

In the preferred embodiment, the radiation generating element 42 is anelectrical planar radiant heater. The radiation generating element 42has at least one flat emitting surface 43 for emitting radiation. Theradiation emitted from the planar radiation generating element 42 isuniformly emitted from the emitting surface 43, that is, at any givenpoint above the emitting surface 43, the radiation power density (W/m²)is uniform. The radiation generating element 42 comprises a sinuatedheating element 46 embedded therein. The radiation generating element 42is made of a highly emissive material which is preferably ceramic,similar to the Watlow Raymax™ ceramic fiber radiant heater. Theradiation generating element 42 can also be made from copper, aluminum,or any other suitable material capable of operating in the 500°-1000° K.temperature range and may be chemically blackened or etched as known inthe art.

The operating temperature of the radiation generating element 42 iscontrolled by a temperature control means 54,56. The temperature controlmeans 54 may include a closed loop temperature control using athermocouple or other thermostatic means. In the alternative, control ofthe operating temperature of the radiation generating element 42 can bedissipation limited, that is, the operating temperature of the radiationgenerating element 42 can be controlled by introducing a quantity ofenergy into the radiation generating element 42 calculated to achieve aparticular operating temperature, limited by dissipation.

In the preferred embodiment of the apparatus, a thermocouple controlunit 56 having a probe or thermal sensor 54 embedded within the baseblock 44 of the radiation generating element 42 relays temperatureinformation to the thermocouple control unit 56 via wire 55. The controlunit 56, located within the housing 40, controls the temperature of theradiation generating element 42 by varying the amount of energyintroduced into the radiation generating element 42 thereby adjustingmaintaining the temperature of the radiation generating element 42 at adesired temperature.

According to the present invention, the stagnating means comprises astagnating element 48 for stagnating flow of a fluid medium, such asair, adjacent the radiation generating element 42. A first zone 77 islocated adjacent the radiation generating element 42 and extends to apoint where it meets a second zone 78. The first 77 and second 78 zonesinclude at least one pocket 73. The second zone 78 is located betweenthe first zone 77 and the subject or object 34 being irradiated. Thesecond zone 78 may begin where the first zone 77 ends, that is, thesecond zone 78 begins at a point within the conduits 70 where the firstzone 77 ends. In other words, the first zone 77 and the second zone 78may intersect each other at a spaced apart distance from the second ends72 of the conduits 70. The fluid medium extends from the radiationgenerating element 42 into the first zone 77 and thereafter into thesecond zone 78. The fluid medium is homogenous, that is, the fluidmedium consists of a single constituent such as air, a liquid, a gas, ora vacuum which is evenly and consistently distributed throughout thefirst 77 and second 78 zones. The fluids comprising the medium can bepure liquids or gases or can be mixtures of liquids or gases. The fluidmedium must also be continuous, that is, there can be no breaks or gapsin the medium as it extends into and through the first 77 and second 78zones. For example, in the preferred embodiment, the fluid medium isair. The air extends from the radiation generating element through thefirst zone 77 to the second zone 78 without any interruption. In otherwords, there are no impediments or barriers disposed within the mediumwhich can divide or dissect the fluid medium into discrete and/ordisjunct regions.

The fluid medium extends from the radiation generating element 42through the pocket 73 and through the first 77 and second 78 zones. Thestagnating element 48 is comprised of at least one pocket 73, a sub-zoneof the first 77 and second 78 zones, located within a conduit or tube 70having first 71 and second 72 open ends, and a wall portion 74 extendingtherebetween. The pockets 73 are only a sub-zone or subset of the entirefirst 77 and second 78 zones.

In the preferred embodiment, the stagnating element 48 comprises aplurality of these pockets 73 with each of the pockets being hexagonallyshaped. The hexagonally shaped pockets 73 are arranged in a honeycomb orgrille-like structure. The honeycomb structure allows for a greaternumber of pockets 73 to be utilized for stagnating a fluid medium, suchas air, in the first zone 77 located adjacent the radiation generatingelement 42.

The conduits 70 defining the pockets 73 are conventionally fabricatedfrom a material having low thermal conductivity such as stainless steel,a ceramic material, glass or the like. The inner surfaces 75 of the wallportion 74 of each of the conduits 70 are highly reflective at infraredwavelengths, that is, black body infrared radiation emitted by theradiation generating element 42 is not absorbed by the inner surfaces 75of the conduits 70, but, rather, the inner surfaces 75 reflect theinfrared radiation in a direction away from the radiation generatingelement 42. The inner surface can comprise coating or plating with suchmaterials as aluminum, nickel, gold, stainless steel, or the like.

Each of the conduits 70 defining the pockets 3 have a length L, adiameter D, and a wall thickness T. In the preferred embodiment, thecross-sectional area of the wall thickness T of each of the wallportions 74 of the conduits 70 is less than the cross-sectional areas ofeach of the pockets 73 defined by the wall portions 74. In other words,when a cross-section of a conduit 70 defining each of the pockets 73 isanalyzed, the area occupied by the wall thickness T should be less thanthe area of the pocket 73 defined by the wall portion 74. By maintaininga greater ratio of pocket area to wall thickness area, conductive heatloss is minimized and increases power transfer efficiency of theradiation generating element 42. In addition, in the preferredembodiment, the length L of each of the conduits 70 is substantiallygreater than the diameter D of the pockets 73 defined by the wallportions 74. In other words, each conduit 70 should have a length Lwhich is several times greater than the diameter D of the pockets 73 asdefined by the wall portions 74. Ideally, the aspect ratio of conduit ortube 70 length (L) to diameter (D) should be approximately 5-6:1. Thisrelationship more effectively prevents the flow of air from travellingdown the pockets 73 defined by the conduits 74 to the radiationgenerating element 42 and, thus, better inhibits convective heat lossfrom the radiation generating element 42. The stagnating element 48prevents convective heat transmission by utilizing the inherentviscosity of the medium, i.e., air, to prevent the flow of the medium.By maintaining aspect ratio of conduit or tube 70 length (L) to diameter(D) in the range of approximately 5-6:1, the viscosity of airsubstantially prevents the sustenance of convective air currents. Inother words, air is not able to freely flow within the conduits or tubes70.

A sealing means is disposed between the radiation generating element 42and the first open end 71 of each of the conduits 70 making up thestagnating element 48 to form a substantially air-tight seal betweeneach of the conduits 70 and the radiation generating element 42. Thesealing means inhibits convective heat loss from the radiationgenerating element 42 by preventing circulation of air at or near theradiation generating element 42. In other words, creating the sealbetween each of the conduits 70 and the radiation generating element 42prevents air from circulating between the radiation generating element42 and the first open end 71 of each of the conduits 70 and, thereby,limiting the convective removal of heat from the radiation generatingelement 42 by the air. Limiting convective heat loss increases the powertransfer efficiency of the radiation generating element 42. The sealingmeans may be any suitable means for creating a seal such as a placingthe stagnating element 48 in close proximity to the radiation generatingelement 42 to create an interface between the stagnating element 48 andthe radiation generating element 42 which prevents air flow at theinterface. Alternatively, the sealing means may comprise a gasket 76placed between the radiation generating element 42 and the stagnatingelement 48 may be used to create the seal between the conduits 70comprising the stagnating element 48 and the radiation generatingelement 42. The gasket 76 may be located about a periphery of theradiation generating element 42 for sealing and separating the conduits70 from the radiation generating element 42. The gasket 76 may be madefrom material capable of withstanding sustained temperatures in excessof the operating temperatures of the radiation generating element 42.The preferred material being a ceramic material such as ceramic paper.Any suitable means, as is known in the art, for creating a seal may beemployed.

The stagnating element 48 and the radiation generating element 42 areheld in place within the housing 40 by compression. The specularreflector plate 52 reflects radiation emitted from side opposite theemitting surface 43 away from the interior of the housing 40. The layerof ceramic fiber insulation 50 insulates the interior of the housing 40from intense heat generated by the radiation generating element 42. Thelayer of insulation 50 is spaced apart from the radiation generatingelement 42 but may be located in contact with the radiation generatingelement 42. The open face 41 of the housing 40 allows for emission ofthe black body infrared radiation from the radiation generating element42. The housing 40 also houses air circulating means which comprises afan 60 for cooling an electric motor 61 contained in the fan housing 58and the cylindrical fan 57 to the force flow of air through a ductportion 59 of the fan housing 58 to cool external tissues duringirradiation. Fan forced air exits the housing 40 through the adjustablelouver assembly 62. The adjustable louver assembly 62 allows the flow ofair to be directed over the external tissues.

In the first alternative embodiment of the present invention shown inFIGS. 5 and 6, the black body infrared radiation generating apparatus 80is comprised of a radiation source 96, focusing means for focusingradiation emitted by the radiation source 96, and stagnating means forstagnating air adjacent the radiation source.

The radiation generating apparatus 80 is a focused source, that is, theinfrared radiation emitted is concentrated per unit area. In otherwords, at any given point adjacent the radiation source 96, theradiation power density (W/m²) is not uniform. The radiation source 96in the first alternative embodiment is a light bulb 97. The light bulb96 may be of any suitable type or size which is capable of emittingradiant energy. A quartz halogen light bulb is preferable. The lightbulb 97 has a base portion 98 and a light emitting portion 99. The baseportion 98 of the bulb 97 is removably secured in an electrical socket94 as is commonly used in the art. This alternative embodiment 80 alsoincludes means for controlling the temperature of the radiation source96. As shown in FIG. 5, a thermo-sensing probe 124 is located in contactwith the tubular element 100 for relaying temperature information to theremote electrical temperature control unit (not shown) similar to theunit 54 previously described. Additionally, the temperature of thesource 96 may be dissipation limited as was previously described.

The focusing means comprises a reflector 126 for focusing the radiationemitted by the radiation source 96 on the biological tissue, the tubularelement 100 which encloses the radiation source 96, and adjustment meansfor adjusting the focus of the radiation emitted by the radiation source96.

The reflector 126 is used to adjustably focus the radiation emitted fromthe radiation source 96 on a limited portion of the biological tissue.The reflector 126 is oriented about the radiation source 96, with theradiation source 96 axially located. The shape of the reflector 126 isessentially ellipsoidal. However, the shape of the reflector 126 is notlimited to that of an ellipse. The shape of the reflector 126 may beparabolic, hyperbolic or any other shape depending on the application,that is, depending on the area of the tissue to be treated, the shape ofthe reflector 126 is chosen to give a radiation pattern commensuratewith the area of tissue to be irradiated. The reflector 126 has aninternal reflecting surface 130. The reflecting surface 130 should havespecular or mirror-like properties. In order to obtain a reflector 126having specular properties, the reflector 126 should be constructed of amaterial or having a coating that is reflective to infrared wavelengths,such as aluminum, silver, nickel, chromium, or gold. In order to limitthe material cost, the reflector 126 can be constructed of lessexpensive materials such as plastic; subsequently the reflecting surface130 can be plated or coated with better infrared reflecting materials.

The tubular element 100 includes first 102 and second 104 open ends anda wall portion 106 extending therebetween. The tubular element 100 isoctagonally shaped and substantially encloses the radiation source 96.The shape of the tubular element 100 may be any shape capable ofenclosing the radiation source 96, however, the shape must be such thata substantially air-tight seal can be formed between the tubular element100 and the stagnating element 132. The tubular element 100 isconstructed of aluminum but, can also be constructed of copper or othersuitable thermally conducting materials. The tubular element 100includes inner 108 and outer surfaces 110. The outer surface 110 of thetubular element 100 is etched and blackened to increase its emissivity.The etching may be done chemically or mechanically and the blackeningmay be accomplished by chemical means, however both the etching andblackening of the tubular element 100 may be accomplished by any meansknown in the art. The radiation source 96 is axially located within thetubular element 100.

The tubular element 100 also includes a plurality of spaced apartapertures 114 provided therein permitting a controlled amount of visiblelight from the radiation source 96 to escape from the tubular element100. The visible light from the radiation source 96 exits the tubularelement 100 through the apertures 114, travels through the stagnatingelement, and strikes the reflector 126 and is focused and becomesvisible to an observer. Because infrared radiation is not in the rangeof light visible to a human eye, this controlled amount of visible lightfrom the radiation source 96 is used to obtain an approximation of boththe size and the focal point of the infrared radiation emitted from theradiation source 96.

The means for adjusting the focus of the radiation is comprised of theslidable cylinder 92 and sleeve 88. The slidable cylinder 92 has firstend 93 and second end 95 and is constructed of a thermoconductingmaterial preferably stainless steel. The first end 93 of the slidablecylinder 92 slidingly passes through the aperture 128 in the reflector126 and is supported by the sleeve 88. The sleeve 88 may be constructedof a low thermally conductive material such as aluminum, and has aplurality of threaded apertures 89 for receiving set screws or fasteners90 for adjustably securing the slidable cylinder 92 once a desired sizeand focal point of the emitted radiation is established. The second end95 of the slidable cylinder 92 is attached to the socket 94 containingthe radiation source 96. The adjustment means provides a mechanism bywhich the radiation source 96 can be moved relative to the reflector 126for focusing the radiation emitted from the radiation source 96.

In order to adjust the focus of the radiation generating apparatus 80,the operator first loosens the set screws 90 of the sleeve 88, manuallyadjusting the position of the radiation generating element 96 by slidingtoward or away from the reflector 126 until the desired focal point isobtained, and then re-tightening the set screws. FIG. 3 shows theradiation generating source 96 in its fully retracted position.Additionally, the focus of the apparatus 80 may be accomplished byutilizing the well known focusing helix as is commonly employed inadjustable lenses such as camera lenses.

The cylindrically shaped housing 82 encloses the sleeve 88 and abuts thereflector 126. The cylindrically shaped housing 82 contacts the sleeve88 to allow for conductive heat transfer from the sleeve 88 to thehousing 82. The housing 82 includes a plurality of spaced-apart coolingfins 84 located circumferentially about the housing 82 for dissipatingheat generated by the radiation source 96 and transferred through thesliding cylinder 92 to the sleeve 88. The housing 82 is constructed of athermally conducting material, preferably aluminum. The housing 82 maybe secured by known fastening means.

In the embodiment shown in FIG. 6, the stagnating element 132 forstagnating air adjacent the radiation source 96 utilizes the honeycombstructure as previously described, however, the stagnating element 132surrounds the tubular element 100 containing the radiation source 96.The stagnating element 132 is comprised of eight individual sections 133of honeycomb material arranged in an octagonal configuration. However,the arrangement of the honeycomb material is not limited to theoctagonal configuration and can include any geometric arrangementcapable of surrounding the radiation source 96. The individual sectionsare joined by suitable means such as welding to form a hollow structurecapable of surrounding the radiation source 96.

The front cap 122 and the rear cap 116 cover a first 134 end and asecond 136 end, respectively, of the stagnating element 10. The frontcap 122 and the rear 116 cap each have a shape that is identical to theconfiguration of the individual sections 133 comprising the stagnatingelement 132. For example, if the sections of honeycomb material arearranged in an octagonal configuration, the front cap will have anoctagonal shape. The front cap 122 and the rear cap 116 are placed inforce fitting frictional contact with the respective ends of theconduits of the stagnating element 132. The rear cap 116 includes anaperture 118 for receiving the slidable cylinder 92. The axial flange120 of the rear cap 116 surrounds the slidable cylinder 92 and isaffixed to the slidable cylinder 92 by welding or other suitable means.

In second alternative embodiment of the present invention shown in FIG.7, the structure of the individual components are the same or similar tothose enumerated in the preferred embodiment as described above with theexception of the components listed below. The infrared heating apparatus150 comprises the planar radiation generating element 158, the pair ofair stagnating elements 160, the reflector 162, and elongate support 152connected to a support stand, not shown. The radiation generatingelement 158 is similar to that designated by the numeral 42 in FIG. 2and is attached to a first end 154 of the elongate support 152. However,in this alternative embodiment, both emitting surfaces 159 of theradiation generating element 158 are utilized as radiation emittingsurfaces 159. By utilizing two radiation emitting surfaces 159, theradiation emitting surface area is increased and the efficiency of theradiation generating apparatus is thereby increased. Each of theindividual stagnating elements 160 of the second alternative embodimentis similar to that designated by the numeral 48 of FIG. 2 and aremounted one on each emitting surface 159 of the radiation generatingelement 158.

The reflector 162 is affixed to the elongate support 152. The elongatesupport 152 is made from a material having low thermal conductivity suchas a temperature resistant plastic. A remote electrical temperaturecontrol means, not shown, similar to that used with respect to theembodiment shown in FIGS. 5 and 6 is utilized in conjunction with theradiation generating element 158 to regulate the temperature of theradiation generating element 158. The reflector 162 is oriented aboutthe radiation generating element 158, with the radiation generatingelement 158 axially located. The reflector 162 is essentially "V"shaped. However, the shape of the reflector 162 is not limited to being"V" shaped. The shape of the reflector 162 can be any other shapedepending on the application, that is, depending on the area of thetissue to be treated, the shape of the reflector 162 is chosen to give aradiation pattern commensurate with the area of tissue to be irradiated.

In operation, the portion of the body 34 to be treated, disposed in thesecond zone 78, is placed in the fluid medium in spaced apartrelationship to the infrared heating apparatus 10,80,150. An electricalcurrent, not shown, is applied to the radiation generating element42,96,158. The temperature of the radiation generating element 42,96,158is maintained in the range of about 500°-1000° K. by the thermocoupletemperature control unit 56 which varies the amount of electricalcurrent supplied to the radiation generating element 42,96,158, therebycontrolling the temperature of the radiation generating element42,96,158. Controlling the temperature of the radiation generatingelement 42,96,158 in about this temperature range causes the radiationgenerating element 42,96,158 to emit black or grey body infraredradiation with maximum emitted wavelengths (λ_(max)) of approximately3-6 μ, yielding an emission spectrum in the range of about 1-30 μm. Thestagnating element 48,132,160 inhibits the flow of the fluid medium,such as air, in the first zone 77 located adjacent the radiationgenerating element 42,96,158 thereby reducing convective heat loss fromthe radiation generating element 42,96,158 and also inhibiting theheating of the air in the second zone 78 which is located adjacent thefirst zone 77 and spaced apart from the second end 72 of the conduits ortubes 70. This is achieved by each of the conduits or tubes 70 definingthe first 77 and second 78 zones which include pockets 73 for stagnatingor trapping air therein. In addition to reducing convective heat lossfrom the radiation generating element 42,96,158, the conduits or tubes70 inhibit the flow of air by producing the pocket 73 containingstagnant air. This pocket 73 of stagnant air provides an insulativelayer of air between the radiation generating element 42,96,158 and theexternal tissues of the portion of the body 34 being heated located inthe second zone 78. This insulative layer of air reduces the heating ofthe external tissue by preventing the heating of air between theradiation generating element 42,96,158 and the external tissues,thereby, increasing the maximum exposure time allowing for a longer andmore beneficial treatment. In other words, a pocket or zone 73 ofstationary air is maintained allowing for the transmission of radiantenergy in the form of infrared radiation while inhibiting the passage ofthermal energy in the form of convectively heated air thereby allowingthe internal tissues to be heated while protecting the external tissuesfrom damage. The effect of the insulative layer of air increases theefficiency of the radiation generating element 42,96,158 by reducing theamount of heat loss from the radiation generating element 42,96,158 toits surroundings. Since the electrical power coming into the radiationgenerating element 42,96,158 essentially only heats the radiationgeneration element 42,96,158 and, then, is emitted to heat the subject34, very little power is wasted heating up the surrounding air. Theinsulative layer of air trapped by the stagnating element 48,132,160essentially creates a quasi-vacuum around the radiation generatingelement 42,96,158 isolating the radiation generating element 42,96,158from the surrounding air and increasing the power efficiency of theradiation generating apparatus 10,80,150. The black body infraredradiation emitted from the radiation generating element 42,96,158 sothat black body infrared radiation from the radiation generating element42 enters through the first open end 71 and exits through the secondopen end 72 passing through the pockets 73, the first 77 and second 78zones of the stagnating element 48,132,160, and through the fluid mediumto the second zone 78 where it may then be applied to biologicaltissues.

The method is disclosed for heating internal biological tissues of thetype having external tissues without increasing the temperature of theexternal tissues above a predetermined limit where discomfort or damageto the external tissues occurs. The external biological tissues areunderstood to include, but are not to be limited to, human or animalskin and the tissues comprising the skin. The internal biologicaltissues are understood to include, but are not limited to, the tissueslying below the external tissues including muscle, blood vessels, fat,cartilage, bone, tendon, internal organs and the like. Medicalliterature indicates that external tissue temperatures above apredetermined limit of 45° C. can cause discomfort or even damage to theexternal tissues.¹ The method includes the steps of generating blackbody infrared radiation from a black body infrared radiation emittingsource 42,96,158 to cause black body infrared radiation havingwavelengths primarily in a range of about 3-30 μm to be emitted bymaintaining the temperature of the radiation source 42,96,158 in a rangeof about 500°-1000° K., transmitting the radiation through the firstzone 77 and through the second zone 78 to heat the biological tissueslocated in the second zone 78, establishing a continuous and homogenousfluid medium from the black body infrared radiation emitting source42,96,158 into the first zone 77 and into the second 78 zone, placingthe biological tissue in the fluid medium spaced apart from theapparatus 10,80,150, typically in a range of about 1/2-12 inches inspaced apart relationship to the radiation source 42,96,158, andapplying the black body infrared radiation to the biological tissue toirradiate the biological tissue for a period of time sufficient toincrease the temperature of the internal tissue to a therapeutic levele.g., 2 minutes to 6 hours. The method is characterized by stagnatingthe flow of the fluid medium in the first zone 77 to transmission ofheat by convection from the radiation source 42,96,158 and from thefirst zone 77 to the second zone 78 to heat the internal tissues whilepreventing the heating of the external tissues above the predeterminedlimit of 45° C. The temperature increase of the internal biologicaltissues should be in a range of about 2-6° C. in order to achieve thetherapeutic benefits of hyperthermia.² This temperature range has beenfound to be critical in eliciting the beneficial effects ofhyperthermia. The benefits of increasing the temperature of internalbiological tissue include but are not limited to treatment of musclepain and soreness, increasing localized blood flow³, a treatment forcancers or adjuvant therapy in combination with other cancer or tumortreatments⁴ e.g., in combination with ionizing radiation orchemotherapy, treatment for the dermatologic condition of psoriasis⁵,faster healing of wounds⁶, and changes in mood state.⁷ The methodfurther includes the step of circulating air over the external tissueduring the application of the black body infrared radiation to removeany excess heat from the external tissues and provide additional comfortto the subject undergoing this method of treatment.

The general steps of the method previously described may also be used asa method for increasing the localized blood circulation in internalbiological tissues having external tissues and internal tissues withoutincreasing the temperature of the external tissues above thepredetermined limit where discomfort or damage to the external tissuesoccurs. This method is characterized by stagnating the flow of the fluidmedium in the first zone 77 to transmission of heat by convection fromthe radiation source 42,96,158 and from the first zone 77 to the secondzone 78 to heat the internal tissues while preventing the heating of theexternal tissues above the predetermined limit to increase circulationby localized vasodilation of capillaries and blood vessels. In responseto the increased temperature of the internal tissues, the capillariesand blood vessel in the internal tissues undergo vasodilation, i.e., thediameter of these blood carrying vessels increases in order to allow forincreased blood flow. The increased blood flow provides for bettercooling of the tissues being irradiated through increased tissueperfusion and, additionally, provides for increased nutrient deliveryand waste removal from the internal tissues.³

The general steps of the method as disclosed may also be used as amethod for increasing the localized blood circulation in internalbiological tissues of a penis. This method also includes the step ofrepositioning the penis to irradiate the previously unexposed surface ofthe penis and is characterized by stagnating the flow of the fluidmedium in the first zone 77 to transmission of heat by convection fromthe radiation source 42,96,158 and from the first zone 77 to the secondzone 78 to heat the internal tissues of the penis while preventing theheating of the external tissues of the penis above the predeterminedlimit to increase circulation by localized vasodilation of capillariesand blood vessels.

The method is also disclosed for heating an object with black bodyinfrared radiation comprising the steps of generating black bodyinfrared radiation from a black body radiation source 42,96,158,transmitting the black body radiation through a first zone 77 andthereafter through a second zone 78 to heat the object located in thesecond zone 78, establishing a continuous and homogenous fluid mediumform the black body radiation source through the first zone 77 andthrough the second zone 78. The method is characterized by stagnatingthe flow of the fluid medium in the first zone 77 to limit transmissionof heat by convection from the radiation source 42,96,158 and from thefirst zone 77 to the second zone 78. The method also includes the stepof maintaining the temperature of the radiation source 42,96,158 in therange of about 500°-1000° K. The method also includes the step ofgenerating black body infrared radiation having wavelengths primarily inthe range of about 3-30 μm.

EXAMPLES EXAMPLE 1

Using slaughtered pig thighs, a four channel temperature sensor (acustom linear microprobe thermocouple array) was implanted in theinternal tissues of the pig thigh. Four independent digital temperaturemonitoring displays, with a 0.1 degrees C. resolution, were read andrecorded every 2 minutes during the test interval.

An infrared heating apparatus such as that shown in FIGS. 1-4, operatingat nominally 475 watts was set up and electrical current supplied andadjusted until the infrared apparatus generated infrared energy in aspectrum in the range of 3-30 μm. Both transverse air flow from the fanand normal impingement air flow were used to cool the external epidermaltissues during treatment. After 40 minutes of exposure from the infraredsource, the external skin temperature remained under 45° C. Thetemperature of the internal tissues at a depth of approximately 30 mmrose nominally by 4° C. during the period of treatment.

EXAMPLE 2

Data was collected comparing the subject infrared heating apparatusoperating at 475 Watts, such as that shown in FIGS. 1-4, and a standardheat lamp (250 Watt General Electric Infrared Heat Lamp). The radiantpower output (watts) was normalized by adjusting the current supplied toboth the subject infrared heating apparatus and the standard heat lampwas adjusted to give nearly identical radiant power outputs per area oftissue irradiated (W/cm²). As in example 1, slaughtered pig thighs wereused, a four channel temperature sensor (a custom linear microprobethermocouple array) was implanted in the internal tissues of the pigthigh. Four independent digital temperature monitoring displays, with a0.1 degrees C. resolution, were read and recorded every 2 minutes duringthe test interval.

Both the subject infrared heating apparatus and the standard heat lampwere operating at nominally 0.92 W/cm² and 0.95 W/cm², respectively. Forthe subject infrared heating apparatus, transverse air flow from the fanwas used to cool the external epidermal tissues during treatment.Comparing the data points taken after approximately 15 minutes ofexposure, the increase in internal temperature, recorded atapproximately 32 mm under the surface of the skin, of both the subjectinfrared apparatus and the standard heat lamp were approximately 2° C.during the period of treatment. However, for the standard heat lamp, thetemperature increase of the external tissues was approximately 36° C.compared to only approximately a 12° C. external tissue temperatureincrease for the subject infrared heating apparatus for the same periodof treatment. It was observed during this experiment that at the pointat which the temperature of the external tissue had increased by 36° C.,burning and other serious tissue damage had occurred.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims whereinreference numerals are merely for convenience and are not to be in anyway limiting, the invention may be practiced otherwise than asspecifically described.

REFERENCES

1. Meyer JL, Kapp DS, Normal-tissue Effects of Hyperthermia. Front.Radiat. Ther. Oncol. 1989; 23:162-76

2. Robins HI, Dennis WH, Neville AJ, Shecterle LM, Martin PA, GrossmanJ, Davis TE, Neville SR, Gillis WK, and Rusy BF, A Nontoxic System for41.8° C. Whole-Body Hyperthermia: Results of a Phase I Study Using aRadiant Heat Device, Cancer Research 1985; 45:3937-3944.

3. Hetzel FW, Biologic Rationale for Hyperthermia, Radiol. Clin. NorthAm. 1989 May;27(3):499-508.

4. Dunlop PR, Howard GC, Has Hyperthermia a Place in Cancer Treatment?,Clin. Radiol. 1989 Jan.; 40(1):76-82.

5. Westerhof W, Siddiqui AH, Cormane RH, and Scholten A, InfraredHyperthermia and Psoriasis, Arch. Dermatol. Res. 1987; 279(3):209-10.

6. Gogia PP, Hurt BS, and Zirn TT, Wound Management with Whirlpool andInfrared Cold Laser Treatment, Phys. Ther. 1988 Aug.; 68(8):1239-42.

7. Koltyn KF, Robins HI, Schmitt CL, Cohen JD, and Morgan WP, Changes inMood State Following Whole-body Hyperthermia, Int. J. Hyperthermia,1992; 8(3):305-307.

What is claimed is:
 1. An apparatus for heating an object with blackbody infrared radiation, said apparatus (10,80,150) comprising:aradiation source (42,96,158) for generating black body infraredradiation and emitting said radiation for transmission into a first zone(77) and thereafter into a second zone (78) to heat a body (34) locatedin said second zone (78) by infrared radiation; a stagnating means(48,132,160) disposed in said first (77) and second (78) zones toestablish a continuous and homogenous fluid medium extending from saidradiation source (42,96,158) into said first zone (77) and into saidsecond zone (78) for stagnating the flow of said fluid medium in saidfirst zone (77) to limit transmission of heat by convection from saidradiation source (42,96,158) and from said first zone (77) to saidsecond zone (78), said stagnating means (48,132,160) comprising aplurality of pockets (73), and each of said pockets (73) defined by aconduit (70) having a first open end (71), a second open end (72) and awall portion (74) extending therebetween so that infrared radiation fromsaid radiation source (42,96,158) enters through said first open end(71) and exits through said second open end (72).
 2. An apparatus (80)as set forth in claim 1 wherein said stagnating means (132) surroundssaid radiation source (96).
 3. An apparatus (80) as set forth in claim 4wherein said stagnating means is (132) comprised of eight sections(133), said sections (133) arranged in an octagonal configuration.
 4. Anapparatus (10,80,150) as set forth in claim 1 wherein a by sealing meansis disposed between said stagnating means (48,132,160) and saidradiation source (42,96,158) for limiting air flow.
 5. An apparatus(10,150) as set forth in claim 4 wherein said sealing means (76)comprising ceramic paper.
 6. An apparatus (10,80,150) as set forth inclaim 1 wherein each of said pockets (73) is hexagonally shaped.
 7. Anapparatus (10,80,150) as set forth in claim 1 wherein said pockets is(73) defined by a honeycomb structure.
 8. An apparatus (10,80,150) asset forth in claim 1 wherein said wall portion (74) of each of saidconduits (70) has an inner surface (75) which is highly reflective atinfrared wavelengths.
 9. An apparatus (10,80,150) as set forth in claim1 wherein the cross-sectional area of said wall portions (74) is lessthan the cross-sectional areas of said pockets (73) defined thereby. 10.An apparatus (10,80,150) as set forth in claim 1 wherein each of saidconduits (70) has length (L) which is substantially greater than thediameter (D) of said pockets (73) defined thereby.
 11. An apparatus(10,80,150) as set forth in claim 1 including a temperature controlmeans (56) for maintaining the temperature of said radiation source(42,96,158) in a range of 500°-1000° K.
 12. An apparatus (10) as setforth in claim 1 including an air circulating means (57) for circulatingair over external tissues.
 13. An apparatus (80) as set forth in claim 1wherein said radiation source (96) has means for focusing said infraredradiation.
 14. An apparatus (80) as set forth in claim 13 wherein saidfocusing means includes a specular reflector (126) for focusing saidinfrared radiation on a biological tissue.
 15. An apparatus (80) as setforth in claim 13 wherein said radiation source (96) is defined by alight bulb (97).
 16. An apparatus (80) as set forth in claim 1 wherein ahousing means (100) includes a first open end (102), a second open end(104), and a wall portion (106) extending therebetween, said first (102)and second (104) ends are covered by front (122) and rear (116) caps tosubstantially enclose said radiation source (96) thereby preventingsubstantially all light from escaping from said housing means (100). 17.An apparatus (80) as set forth in claim 16 wherein said housing means(100) includes focusing means for focusing of the infrared radiation.18. An apparatus (80) as set forth in claim 17 wherein said focusingmeans includes a plurality of spaced apart apertures (114) located aboutsaid housing means (100).
 19. An apparatus (10,80,150) for heatinginternal biological tissues of the type having both external tissues andinternal tissues without increasing the temperature of the externaltissues above a predetermined limit where discomfort to the externaltissues occurs, said apparatus comprising:a radiation source (42,96,158)operating in a temperature range of 500°-1000° K. for emitting blackbody infrared radiation; a honeycomb (48,132,160) positioned to occupy acontinuous medium which extends from said radiation source (42,96,158)to the tissues being heated comprised of a plurality of hexagonallyshaped conduits (70), each of said conduits (70) having a first open end(71), a second open end (72), and a wall portion (74) extendingtherebetween such that only said medium extends from said radiationsource (42,96,158) through said first open end (71) and through saidsecond open end (72) to the tissues being heated, said conduits (70)having a length (L) which is substantially greater than a diameter (D)of pockets (73) defined thereby to limit the transmission of heat byconvection through said conduits while preventing absorption of saidradiation other than at the tissues to be heated.
 20. An apparatus(10,80,150) as set forth in claim 19 wherein a by sealing means isdisposed between said conduits (70) and said radiation source(42,96,158) for limiting air flow.
 21. An apparatus (10,80,150) as setforth in claim 19 further characterized by including an air circulatingmeans (57) for circulating air over the external tissues.
 22. Anapparatus (10,80,150) as set forth in claim 19 including a temperaturecontrol means (56) for maintaining the temperature of said radiationsource (42,96,158) in a range of 500°-1000° K.
 23. An apparatus(10,80,150)) as set forth in claim 19 wherein said length (L) is atleast five times greater than said diameter (D).
 24. An apparatus(10,80,150)) as set forth in claim 19 wherein said medium is air.